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/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include "mathimpl.h"
#ifndef SUFF
#define SUFF
#endif
#ifndef float_type
#define float_type double
#endif
#define CONCATX(a,b) __CONCAT(a,b)
#define s(name) CONCATX(name,SUFF)
#define m81(func) __m81_u(s(func))
float_type
s(__ieee754_pow) (float_type x, float_type y)
{
float_type z;
float_type ax;
unsigned long x_cond, y_cond;
y_cond = __m81_test (y);
if (y_cond & __M81_COND_ZERO)
return 1.0;
if (y_cond & __M81_COND_NAN)
return x == 1.0 ? x : x + y;
x_cond = __m81_test (x);
if (x_cond & __M81_COND_NAN)
return x + y;
if (y_cond & __M81_COND_INF)
{
ax = s(fabs) (x);
if (ax == 1.0)
return ax;
if (ax > 1.0)
return y_cond & __M81_COND_NEG ? 0 : y;
else
return y_cond & __M81_COND_NEG ? -y : 0;
}
if (s(fabs) (y) == 1.0)
return y_cond & __M81_COND_NEG ? 1 / x : x;
if (y == 2)
return x * x;
if (y == 0.5 && !(x_cond & __M81_COND_NEG))
return m81(__ieee754_sqrt) (x);
if (x == 10.0)
{
__asm ("ftentox%.x %1, %0" : "=f" (z) : "f" (y));
return z;
}
if (x == 2.0)
{
__asm ("ftwotox%.x %1, %0" : "=f" (z) : "f" (y));
return z;
}
ax = s(fabs) (x);
if (x_cond & (__M81_COND_INF | __M81_COND_ZERO) || ax == 1.0)
{
z = ax;
if (y_cond & __M81_COND_NEG)
z = 1 / z;
if (x_cond & __M81_COND_NEG)
{
if (y != m81(__rint) (y))
{
if (x == -1)
z = (z - z) / (z - z);
}
else
goto maybe_negate;
}
return z;
}
if (x_cond & __M81_COND_NEG)
{
if (y == m81(__rint) (y))
{
z = m81(__ieee754_exp) (y * m81(__ieee754_log) (-x));
maybe_negate:
/* We always use the long double format, since y is already in
this format and rounding won't change the result. */
{
int32_t exponent;
u_int32_t i0, i1;
GET_LDOUBLE_WORDS (exponent, i0, i1, y);
exponent = (exponent & 0x7fff) - 0x3fff;
if (exponent <= 31
? i0 & (1 << (31 - exponent))
: (exponent <= 63
&& i1 & (1 << (63 - exponent))))
z = -z;
}
}
else
z = (y - y) / (y - y);
}
else
z = m81(__ieee754_exp) (y * m81(__ieee754_log) (x));
return z;
}
strong_alias (s(__ieee754_pow), CONCATX (s(__pow), _finite))
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